Military VIPs (3,5)
(Other definitions for brass that I've seen before include "Rhino" , "Nerve (but not of steel!)" , "Copper-zinc alloy" , "Readies" , "Boldness" .)
(Other definitions for top brass that I've seen before include "Highest-ranking officials with best yellow alloy" , "most important officials" , "VIPs" , "military leaders" , "Leadership" .)